1. Field of the Invention
The present invention relates to an image display apparatus, a manufacturing method of the image display apparatus, and a functional film.
2. Description of the Related Art
Conventionally, as an electron-emitting device, a cold cathode electron-emitting device has been known. As a cold cathode electron-emitting device, a surface conduction electron-emitting device, a field emission type electron-emitting device (hereinafter, referred to as an FE type electron-emitting device), a metal-insulator-metal type electron-emitting device (hereinafter, referred to as an MIM type electron-emitting device) or the like have been known.
In Japanese Patent Application Laid-Open (JP-A) No. H10 (1998)-326583 (U.S. Pat. No. 6,677,706, EP No. 0866491), and JP-A No. 2003-229079 (U.S. Pat. No. 6,800,995), the applications to the image display apparatus of the surface conduction electron-emitting device and the image display apparatus of the FE type electron-emitting device are disclosed.
In JP-A No. 2001-281442, an optical filter provided on the surface of the image display apparatus is disclosed. In addition, in JP-A No. 2006-189783 and JP-A No. 2006-189784 (International Publication No. 2006/062251), an antireflection film with a conductive layer for a field emission display is disclosed.
FIG. 9 is an oblique perspective figure showing an example of a display panel of a flat type image display apparatus using an electron-emitting device. FIG. 9 also shows its inner structure.
In FIG. 9, a reference numeral 10005 denotes a rear plate (a first substrate), a reference numeral 10006 denotes a side wall, and a reference numeral 10007 denotes a face plate (a second substrate). Further, the rear plate 10005, the side wall 10006, and the face plate 10007 form an airtight container for maintaining the inner space of a display panel vacuum.
On the rear plate (the first substrate) 10005, N×M pieces of electron-emitting devices 10002 are formed. In addition, each of the electron-emitting devices 10002 is connected to a row wiring 10003 and a column wiring 10004, respectively, as shown in FIG. 9. A part configured by these electron-emitting devices 10002, row wiring 10003, and column wiring 10004 is referred to as an electron source.
On the lower face (the face on the side of the first substrate; a first face) of the face plate (the second substrate) 10007, a light emitting film 10008 is provided. In addition, on the face at the side of the rear plate 10005 of the light emitting film 10008, a metal back (an anode electrode) 10009 made of Al (aluminum) or the like is provided.
External terminals Dx1 to DxM, external terminals Dy1 to DyN, and an external terminal Hv are ones for electrically connecting this display panel to a drive circuit. Then, each of the external terminals Dx1 to DxM is electrically connected to each of the row wirings 10003 of an electronic source. Each of the external terminals Dy1 to DyN is electrically connected to each of the column wirings 10004 of an electronic source. The external terminal Hv is electrically connected to the metal back 10009.
In addition, the inner space of the airtight container is held vacuum about −6th power of 10 [Torr] (about 1.33*−4th power of 10 [Pa]). The display panel shown in FIG. 9 is provided with a supporting member (referred to as a spacer or a rib) 10010 for supporting air pressure to be added to the airtight container from the inside of the airtight container. A distance between the first substrate 10005 having the electron source provided thereon and the face plate 10007 having the light emitting film 10008 thereon is practically maintained in the range of 500 μm to 10 mm.
Upon driving of the image display apparatus using the above-described display panel, a voltage is applied to each of the electron-emitting devices 10002 through the external terminals Dx1 to DxM and the external terminals Dy1 to DyN. Then, an electron is emitted from each of the electron-emitting devices 10002. At the same time, by applying a high voltage from 1 [kV] to 40 [kV] to the metal back 10009 through the external terminal Hv, the emitted electron is allowed to crash against the light emitting film 10008. Thereby, the light emitting film 10008 emits a light and an image is displayed. Therefore, a partial area (the area where light emission from the light emitting film 10008 can be visually checked) of the upper face of the second substrate 10007 (the face located on the opposite side of the first face located on the side of the first substrate; a second face) is made into an image display area.
Therefore, the surface of the face plate 10007 (the surface on the opposite side of the side where the light emitting film 10008 is located; the second face) has a high voltage being affected by a potential of the metal back 10009 (namely, to be charged). Accordingly, during driving of the image display apparatus (during display of the image) or just after driving of the image display apparatus (just after display of the image), dust in air is attached to the face plate 10007 due to a static electricity.
Therefore, in order to reduce the potential of the image display area of the face plate (the second substrate) 10007, a conductive layer is provided on the image display area of the face plate 10007. Then, grounding this conductive layer on earth, for example, it is possible to prevent charge of the second face of the second substrate.
On the other hand, since a high voltage is applied to the metal back 10009, the electron-emitting device 10002, the row wiring 10003, and the column wiring 10004, which are located on the rear plate 10005 opposed to the metal back, are exposed to a high electric field. As a result, if there is a triple junction or a foreign substance, on which the electric field is concentrated, on the rear plate, the electric field is concentrated there and electric discharge may be generated inside the airtight container.
If electric discharge is generated, the electric charges accumulated on the face plate (typically, the metal back 10009) flow into the electron-emitting device 10002, the row wiring 10003, and the column wiring 10004 or the like. As a result, the electron-emitting device 10002 is destroyed and the drive circuit to be connected to the row wiring 10003 and the column wiring 10004 is destroyed, and this may cause a serious deterioration of an image quality.
Therefore, a method to give a current limiting function to the anode electrode (metal back) 10009 by means of the method described in JP-A No. H10 (1998)-326583 or the like has been suggested.
However, if charging inhibition processing is provided on the surface of the face plate by grounding the conductive layer as described above while giving the current limiting function to the anode electrode, a serious deficit of a pixel may be caused.
It seems that this may be caused because the apparent electric charge amount of the metal back 10009 is increased since a surface resistance (a sheet resistance) of the conductive layer is set to be lower than the apparent surface resistance of the metal back, so that the current limiting function of the second substrate is decreased when the electric discharge is generated inside the image display apparatus.
Accordingly, it is necessary to provide the conductive layer so as to prevent decrease of the current limiting effect of the metal back (the anode electrode) 10009 and prevent the electric charge of the surface of the image display apparatus.